Mohamad Pharoan, a Syrian-born Muslim who entered the US in 1992 and became a citizen in 1996, was supposed to serve lunch at a banquet where George Bush raised $1m (£575,000) for his re-election campaign. He was escorted from the Hyatt Regency hotel in Baltimore, where he has worked for seven years, after just one question from a manager: "Is your name Mohamad?"

After initially denying involvement, the secret service admitted it was responsible for sending Mr Pharoan home. The decision was not taken because he was Arab or Muslim, it said. A spokesman said: "The problems stemmed from confusion over a work schedule."

Mr Pharoan said the rota had been distributed a week in advance and his name had been supplied to the authorities for background checks.